How is fuelConsumption calculated?

Ólavur 8 years ago

I am trying to understand the attribute fuelConsumption which gives a value of 4313.1336 l/h in my example.

What does this mean or how is this calculated? How can I use this for something uesful?

"id": 5440983,
        "attributes": {
            "hdop": 118,
            "ignition": false,
            "status": 0,
            "odometer": 5460919,
            "power": 11.7529296875,
            "temp1": 14.521484375,
            "battery": 4.15283203125,
            "geofenceIn": 0,
            "geofenceAlarm": 0,
            "event": 1,
            "distance": 5.66,
            "totalDistance": 3926460.33,
            "motion": false,
            "coolantTemperature": 89,
            "rpm": 755,
            "obdSpeed": 0,
            "fuel": 19,
            "clearedDistance": 4532,
            "fuelConsumption": 4313.1336,
            "eventMask": 512
        },
Anton Tananaev 8 years ago

What protocol are you using? The value is reported by your device. Possibly it's decoded incorrectly, but need HEX sample and documentation to check.

Ólavur 8 years ago

I am using the Ulbotech protocol. Here is a screenshot from the protocol description:

Fuel consumption

Also attached is an HEX example:

Fuel consumption example

Anton Tananaev 8 years ago

Please provide sample from your device, expected value and fuel type.

Ólavur 8 years ago

Ok, here is an example from a live car:

2017-10-10 12:21:31 DEBUG: [4B427A3C: 5072 < 185.74.208.107] HEX: f801010868323026528734a16f69ba010e03b4df71ff98359100530137006a0304024200000404016b259f0506035118fa221706080000000000000000070e310582410c177a310d534131bc540804812e41000f040015f661100101d1bcf8
2017-10-10 12:21:31 DEBUG: [4B427A3C: 5072 > 185.74.208.107] HEX: f801fef80104aef8
2017-10-10 12:21:31  INFO: [4B427A3C] id: 868323026528734, time: 2017-10-10 12:21:30, lat: 62.18533, lon: -6.80203, speed: 44.8, course: 311.0

From the data:

f801010868323026528734a16f69ba010e03b4df71ff98359100530137006a0304024200000404016b259f0506035118fa221706080000000000000000070e310582410c177a310d534131bc540804812e41000f040015f661100101d1bcf8

This part is the fuelconsumption: 0804812e4100

08: data ID
04: data length
812e4100: in decimal 2167292160

The web interface shows FuelConsumption: 216729.22 l/h

But according to the Ulbotech protocol in the attached picture above this should be:

Real fuel consumption (unit liter) = 2167292160/10000/2.364 = 91679.03 l

Is this a bug? Or maybe this could be fixed using computed attributes?

Anton Tananaev 8 years ago

Yes, it can be fixed with computed attributes.

Ólavur 8 years ago

Ok, I managed to fix it with fuelConsupmtion / 10000 / 2.364

But is it possible to change the unit from l/h to l only?

Anton Tananaev 8 years ago

It means that it's not really consumption. It's total fuel used.

Ólavur 8 years ago

Yes, i know. That is why I would like to change the unit from l/h to l. That is not possible?

Anton Tananaev 8 years ago

There is no standard attribute for that. You can try fuel level, but it's not really the same.

Ólavur 8 years ago

Ok, thanks. Maybe I can figure out using some CSS or jQuery trick

Thanks.